Strained fin structures and methods of fabrication

Abstract

Methods for fabricating a strained fin structure are provided which include: providing a virtual substrate material over a substrate structure, the virtual substrate material having a virtual substrate lattice constant and a virtual substrate lattice structure; providing a first material over a region of the virtual substrate material, the first material acquiring a strained first material lattice structure by, in part, conforming to the virtual substrate lattice structure; and etching a first fin pattern into the first material. The method may include providing a second material over a second region of the virtual substrate material, the second material acquiring a strained lattice structure by, in part, conforming to the virtual substrate lattice structure, and etching a fin pattern into the second material. The resultant device may have tensile strained fin structures or compressively strained fin structures, or both.

1 . A method comprising:
 fabricating a strained fin structure, the fabricating comprising:   providing a virtual substrate material over a substrate structure, the virtual substrate material having a virtual substrate lattice structure and a virtual substrate lattice constant;   providing a first material over a region of the virtual substrate material, the first material having a first material lattice constant different from the virtual substrate lattice constant, the first material acquiring a strained first material lattice structure via, in part, conforming to the virtual substrate lattice structure; and   etching a first fin pattern into the first material, the first fin pattern including at least one first material fin extending above the region of the virtual substrate material.   
     
     
         2 . The method of  claim 1 , wherein the region of the virtual substrate material is a first region, and the method further comprises providing a second material over a second region of the virtual substrate material, the second material having a second material lattice constant different from the virtual substrate lattice constant and the first material lattice constant, the second material acquiring a strained second material lattice structure via, in part, conforming to the virtual substrate lattice structure, and wherein the etching further comprises etching a second fin pattern into the second material, the second fin pattern including at least one second material fin extending above the second region of the virtual substrate material. 
     
     
         3 . The method of  claim 2 , wherein one of the strained first material lattice structure or the strained second material lattice structure is a tensile strained lattice structure, and the other of the strained first material lattice structure or the strained second material lattice structure is a compressively strained lattice structure. 
     
     
         4 . The method of  claim 3 , wherein the first material lattice constant is smaller than the virtual substrate lattice constant, and the strained first material lattice structure is the tensile strained lattice structure. 
     
     
         5 . The method of  claim 3 , wherein the second material lattice constant is larger than the virtual substrate lattice constant, and the strained second material lattice structure is the compressively strained lattice structure. 
     
     
         6 . The method of  claim 3 , wherein the virtual substrate material comprises relaxed silicon-germanium (Si 1-x Ge x ) material. 
     
     
         7 . The method of  claim 6 , wherein silicon to germanium in the relaxed silicon-germanium is about 50% silicon to 50% germanium. 
     
     
         8 . The method of  claim 6 , wherein providing the virtual substrate material comprises epitaxially growing a silicon-germanium layer over the substrate structure, implanting carbon into the silicon-germanium layer to form a silicon-germanium-carbon layer, and annealing the silicon-germanium-carbon layer to form the relaxed silicon-germanium material. 
     
     
         9 . The method of  claim 8 , wherein epitaxially growing the silicon-germanium material further comprises epitaxially growing a plurality of silicon-germanium layers, and implanting carbon further comprises implanting carbon into one or more of the plurality of silicon-germanium layers to facilitate forming the relaxed silicon-germanium material. 
     
     
         10 . The method of  claim 3 , wherein the first material comprises silicon, and the first material acquires the tensile strained lattice structure. 
     
     
         11 . The method of  claim 3 , wherein the second material comprises germanium, and the second material acquires the compressively strained lattice structure. 
     
     
         12 . The method of  claim 3 , wherein the providing the first material comprises epitaxially growing the first material on the first region of the virtual substrate material, and wherein the providing the second material comprises epitaxially growing the second material on the second region of the virtual substrate material. 
     
     
         13 . The method of  claim 3 , wherein the etching comprises anisotropically etching the first fin pattern and the second pattern into the first material and the second material, respectively. 
     
     
         14 . A device, comprising:
 a substrate structure;   a virtual substrate material over the substrate structure, the virtual substrate material having a virtual substrate lattice constant and a virtual substrate lattice structure;   at least one first fin extending above a region of the virtual substrate material, the first fin comprising a first material with a strained first material lattice structure substantially conforming to the virtual substrate lattice structure, the first material having a first material lattice constant different from the virtual substrate lattice constant.   
     
     
         15 . The device of  claim 14 , wherein the region is a first region, and the device further comprises at least one second fin extending above a second region of the virtual substrate material, the second fin comprising a second material with a strained second material lattice structure substantially conforming to the virtual substrate lattice structure, the second material having a second material lattice constant different from the virtual substrate lattice constant. 
     
     
         16 . The device of  claim 15 , wherein the strained first material lattice structure comprises a tensile strained lattice structure, and the strained second material lattice structure comprises a compressively strained lattice structure. 
     
     
         17 . The device of  claim 16 , wherein the virtual substrate material comprises a relaxed silicon-germanium (Si 1-x Ge x ) material. 
     
     
         18 . The device of  claim 17 , wherein silicon to germanium in the relaxed silicon-germanium material is about 50% silicon to 50% germanium. 
     
     
         19 . The device of  claim 16 , wherein the first material comprises silicon. 
     
     
         20 . The device of  claim 16 , wherein the second material comprises germanium.